Bispyribac Sodium Research Articles

Rapid and Accurate Validated Potentiometric Method for Bispyribac Herbicide Assessment in Rice and Agricultural Wastewater

A new validated method based on potentiometric transduction for bispyribac herbicide assessment in commercial formulations, rice and wastewater samples is fabricated and characterized. Sensors are based in terms of their fabrication on tridodecyl methyl ammonium chloride (TDMAC) as recognition material. TDMAC was plasticized in a poly (vinyl chloride) (PVC) matrix to prepare the membrane. Under static modes of operation, the sensors revealed a Nernstian anionic slope of −63.6 ± 0.7 mV/decade within a linear range of 9.1 × 10−6–1.0 × 10−2 in 50 mM phosphate buffer solution (PBS), pH7. The detection limit was 6.0 × 10−6 M. The sensor was successfully introduced in a flow-stream system revealing a Nernstian response of −53.8 ± 1.3 mV/decade over a linear range of 2 × 10−4–1.0 × 10−2 M and lower detection limit of 5.6 × 10⁻⁵ M. The sampling rate was calculated to be (~42 sample/h). Validation of the assay method is presented in detail including accuracy, trueness, bias, between-day variability and within-day variability, and good performance characteristics of the method are obtained. The presented method was successfully introduced to bispyribac determination in different complex matrices such as commercial bispyribac sodium known as (Nominee-kz, 3% soluble liquid (SL)), rice samples and agricultural wastewater samples. The samples were analyzed successfully under both static and hydrodynamic modes of operation. The results obtained were in a good agreement with those obtained by the liquid chromatographic method.

Pregnancy Outcome in Female Rats Exposed to Bispyribac Sodium and Ameliorative Effect of Nigella Sativa Oil

Bispyribac sodium is commonly used as a herbicide worldwide. Few studies had investigated the health impact of exposure to it. Redox homeostasis has a great role during organogenesis through in cell growth, differentiation, and death. The aim of this study is to investigate the redox homeostasis imbalance and teratogenic effect of BPS in female rats exposed to bispyribac sodium (BPS) during organogenesis and evaluates the protective role of Nigella Sativa Oil (NSO). Pregnant female rats were grouped into four groups, negative and positive (NSO) control groups. While the others, BPS with and without NSO treatment groups. Results showed that BPS exposure during the pregnancy led to maternal and fetotoxicity as evidenced by preimplantation, post-implantation loss, reduction in placenta weight, reduction in fetal weight, fetal length, skeletal anomalies (incomplete ossification, misaligned sternbrae), visceral malformation (anophthalmia, microphthalmia, internal hydrocephaly, and microcephaly) and oxidative stress in dams serum. NSO treatment exhibited amelioration in the aforementioned maternal and fetotoxicity against BPS exposure.

Evaluating weed management practices for direct sown drum seeded rice (Oryza sativa) : A review

Increasing labour cost and scarcity has shifted in trend towards mechanization. Rice being a labour-intensive crop method like direct sowing using drum seeder could help in reducing the nursery and transplanting costs. Moreover, chemical weeding for direct sown rice need to be evaluated which could aid in the developing labour crisis. This review article focuses on the chemical weed management practices for direct sown rice. Pre-emergence (PE) herbicides like pretilachlor, anilofos and pendimethalin along with post-emergence herbicides (POE) like azimsulfuron and bispyribac sodium at different dosages and combinations are evaluated using available literature in contrast to manual hand weeding and mechanical weeding practices. It is a known fact that hand weeding is the best management practice till date and chemical combinations showing comparable performance to hand weeding can be chosen for further evaluation. It could be enlightened that the use of pretilachlor as PE followed by bispyribac sodium as POE have shown to be an appropriate, cost efficient weed management practice. Based on this the recommended dosage for application for pretilachlor @ 750 g (active ingredient) a.i./ha on 8 days after sowing (DAS); and bispyribac sodium @ 25 g a.i./ha on 30 DAS for direct sown drum seeded rice could enhance the weed control efficiency.

Bio-efficacy of herbicide combinations for control of weeds in transplanted rice (Oryza sativa)

The present study during kharif 2013-14 at Professor Jayashankar State Agricultural University, Hyderabad, Telangana to study the efficiency of herbicide combinations for controlling weeds in rice. The study comprised 14 treatments in Randomized block design replicated thrice. During both years of investigation the higher weed control efficiency and herbicide efficiency index was noticed with hand weeding twice at 25 and 45 DAT, pyrazosulfuron ethyl 20 g/ha as PE at 3 DAT followed by manual weeding at 25 DAT and pretilachlor 750 g/ha as PE at 3 DAT followed by metsulfuron methyl + chlorimuron ethyl 4 g/ha as PoE at 25 DAT. Significantly higher grain yield and gross returns were noticed with hand weeding twice at 25 and 45 DAT and was comparable with pyrazosulfuron ethyl 20 g/ha as PE at 3 DAT followed by manual weeding at 25 DAT, pretilachlor 750 g/ha as PE at 3 DAT followed metsulfuron methyl + chlorimuron ethyl 4 g/ha as PoE at 25 DAT and bispyribac sodium 20 g/ha + metsulfuron methyl + chlorimuron ethyl 4 g/ha as PoE at 25 DAT. However, pyrazosulfuron ethyl 20 g/ha as pre emergence at 3 DAT followed by manual weeding at 25 DAT noticed higher net returns and B:C ratio.

Chemical Weed Management in Transplanted Rice (Oryza sativa L.) under Rice – Mustard Cropping System

An experiment was conducted at instructional farm Uttar Banga Krishi Viswavidyalaya during kharif season, 2017 to find out a suitable chemical weed management practice in transplanted rice. The experiment was laid out in randomized block design having 12 treatments replicated thrice. The treatments were T1: Weedy check, T2: Weed free, T3: Bispyribac sodium 10% SC @ 20 g a.i ha-1 at 14 DAT, T4: Bispyribac sodium 10% SC @ 30 g a.i ha-1 at 14 DAT, T5: Butachlor 1.5 kg a.i ha-1 at 3 DAT, T6: Pendimethalin 1.0 kg a.i. ha-1 at 3 DAT, T7: Pretilachlor 0.60 kg a.i ha-1 at 3 DAT + 2,4-D sodium salt 0.50 kg a.i ha-1 at 30 DAT, T8: Butachlor 1.5 kg a.i ha-1 at 3 DAT + 2,4-D sodium salt 0.50 kg a.i ha-1 at 30 DAT, T9: Metsulfuron methyl 20% WP @ 8 g a.i ha-1 at 14 DAT, T10: Pretilachlor 0.60 kg a.i ha-1 at 3 DAT + Almix @ 20 g a.i. ha-1 at 21 DAT, T11: Butachlor 1.5 kg a.i. ha-1 at 3 DAT + Bispyribac sodium 10% SC @ 20 g a.i ha-1 at 21 DAT and T12: Almix @ 20 g a.i ha-1 at 21 DAT. The rice variety used in the experiment was MTU 1075. It was observed that different herbicides treatments influenced weed control efficiency, weed index and yield components in transplanted rice. The highest number of filled grains (113.12 panicle-1), 1000 grain weight (22.90 g), grain yield (5.07 t ha-1) and straw yield (7.15 t ha-1) of rice was recorded with weed free (T2) treatment being at par with T11, T4, T3 and T10. In mustard, plots under weed free i.e. T2 treatment in rice performed the best in terms of every yield attribute viz. number of siliqua (77.00 plant-1), number of seeds (20.41siliqua-1), 1000 seed weight (3.14 g) as well as seed yield (1067.46 kg ha-1) and stover yield (2157.40 kg ha-1) being statistically at par with the plots under treatment T11 & plots under treatment T4. It can be concluded that the treatment comprising combination of pre-emergence & post-emergence herbicide like T11 i.e. Butachlor 1.5 kg a.i. ha-1 at 3 DAT + Bispyribac sodium 10% SC @ 20 g a.i. ha-1 at 21 DAT or application of higher dose of efficient & highly effective post-emergent herbicide molecule like T4 i.e. Bispyribac sodium 10% SC @ 30 g a.i ha-1 at 14 DAT can be opted for sufficient control of weeds in transplanted kharif paddy in terai zone of West Bengal to maximize the economic return.

Effects of Water and Weed Management on the Weed Density, Grain Yield, and Water Productivity of Wet-seeded Rice

Shifting from conventional transplanting to direct seeding of rice is an alternative option to save irrigation water and reduce labor cost. Weeds are one of the major challenges in direct seeding. Field experiments in split-plot design were conducted to evaluate the effects of different water and weed management modes on the weed density, grain yield, and water productivity of direct wet-seeded rice during two dry seasons (DSs) in Nueva Ecija, Philippines. Three water management (W) modes were used: continuous flooding (CF); safe alternate wetting and drying (AWD); and modified CF (mCF). The four weed management (M) modes were: unweeded (UW); hand-weeding at 21 and 42 days after seeding [DAS] (HW); application of pre-emergence herbicide [pretilachlor] at 5 DAS (PR); and application of post-emergence herbicide [bispyribac sodium] at 15 DAS (PO). M modes showed significant effects (p < 0.05) on the weed density and grain yields in both years, with UW obtaining the lowest grain yield and highest weed density. No significant differences in grain yields were noted among weed control treatments. They only increased grain yields by 18–52% relative to UW. HW and PR treatments showed maximum yields. The W modes did not affect the grain yields nor the weed density, but water productivity was highest in AWD in both years. The higher grain yield and lower total water input in AWD maximized water productivity relative to the conventional practice of CF.

In-vitro evaluation of rice straw biochars' effect on bispyribac-sodium dissipation and microbial activity in soil.

Dissipation of bispyribac-sodium was estimated in an unamended sandy loam soil and soil amended with rice straw and its biochars in pot culture experiment. Effect of herbicide and amendments on abundance and activity of soil microbial parameters was also assessed by determining soil biological parameters. Amendment type, application rate and soil moisture had differential influence on bispyribac-sodium dissipation and soil's microbial parameters. Amendment of soil with rice straw and its biochars enhanced the dissipation of bispyribac-sodium (DT50=7.55-18.44 days) as compared to unamended soil (DT50=23.13-28.60 days) and dissipation decreased in this order: rice straw >350BC > 550BC>CBC amended soil>unamended soil. Dissipation of bispyribac-sodium decreased with increase in amendment level of rice straw and its biochars in soil. Irrespective of amendment type and application rate, bispyribac sodium was more persistent under submerged conditions than at field capacity and its DT50 was 10.13 to 28.60 and 7.55-27.14 days, respectively. Dehydrogenase, alkaline phosphatase activity and bacterial population indicated that application of the organic amendment decreased negative effects of the herbicide on soil enzymatic activities. These findings prove that biostimulation using rice straw and its biochars has the potential to decrease the persistence of bispyribac-sodium and minimize its environmental hazards.

DECONTAMINATION OF PESTICIDE RESIDUES IN WATER SAMPLES USING COPPER AND ZINC CO-DOPED TITANIA NANOCATALYST

Copper and Zinc co-doped titania nano photocatalyst (Cu-Zn-TiO2 NPC) was fabricated and characterized using room temperature X-ray diffraction (XRD), field emission electron microscopy (FESEM) with high-resolution transmission electron microscopy (HRTEM) and energy dispersion X-ray (EDX). X-ray diffraction studies of the Cu2+-Zn2+/TiO2 show the presence of anatase phase TiO2 and in the sample prepared from 0.05, 0.10, 0.15 and 0.20 mmol have also shown the presence of anatase phase only. The photocatalytic efficiency of the synthesized catalysts was investigated by the photocatalytic degradation of aqueous bispyribac sodium under sun light irradiation, and it was found that the Cu and Zn co-doped TiO2 catalysts has better photocatalytic activity. It can be also showed that with the addition of dopants to titania hinders the growth of nanoparticles. This can be attributed of the fact that there is a more efficient electron-hole creation in Cu and Zn co-doped TiO2 in sunlight, contrary to un-doped TiO2 which can be excited only in UV irradiation. Photocatalytic studies of bispyribac sodium at various conditions such as acidic, basic and neutral reveals that the activity is enormously increased with co-doped TiO2 is proved to be effective for photocatalysis of bispyribac sodium and is more effective in basic medium.

Effect of chemical weed management practices on soil microbial population and yield in direct seeded rice

The use of herbicides in direct-seeded rice may affect the biological properties of the soil and thus influence the nutrient status, health and productivity of the soil. To study the effect of herbicides on soil microbial population and yield of direct-seeded rice. A field experiment was conducted RBD with eleven treatments at Agriculture Research Farm, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India during Kharif 2018. The results revealed that viable microbial population was influenced to varying degrees with different weed control treatments. The maximum bacterial count (14.86 X 106 CFU g-1 soil) was observed under the treatment T4 (Pyrazosulfuron @ 25 g a.i. ha-1 PE fb Bispyribac sodium @ 25 g a.i. ha-1 POE) and minimum bacterial count was found under the treatment T9 (Halosulfuron @ 67.5 g a.i. ha-1 + Azimsulfuron @ 30 g a.i. ha-1 POE) (11.46 X 106 CFU g-1 soil). the maximum actinomycetes count (17.82 X 105 CFU g-1 soil) was observed under the treatment T1 (Pyrazosulfuron @ 25 g a.i. ha-1 PE) and the minimum actinomycetes count was observed under the treatment T6 (Bispyribac sodium @ 25 g a.i. ha-1 POE) (14.05 X 105 CFU g-1and , the maximum fungi count (10.55 X 104 CFU g-1 soil) was observed under the treatment T9 (Halosulfuron @ 67.5 g a.i. ha-1 + Azimsulfuron @ 30 g a.i. ha-1 POE) and the minimum fungi count was observed under the treatment T10 (hand weeding) (7.60 X104 CFU g-1 soil).The maximum grain yield (5.50 t ha-1) was observed in T10 (hand weeding) and it was followed (5.41 t ha-1) by T5 (Pyrazosulfuron @ 25 g a.i. ha-1 PE fb Bispyribac sodium @ 20 g a.i. ha-1 + Pyrazosulfuron @ 20 g a.i. ha-1 POE). T5 fb T4 (5.08 t ha-1) and T9 (4.67 t ha-1) and which was significantly superior over rest of the treatments. The minimum grains yield was recorded (2.70 t ha-1). in T11 (weedy check) as post-emergence were safe for soil microbial populations at recommended rate application of herbicides.

Weed management practices in direct seeded rice ecosystem in north western zone of Tamil Nadu

Field experiments were conducted to study the cost effective weed management practices in direct seeded rice at Regional Research Station, Tamil Nadu Agricultural University, Paiyur 635 112, Tamil Nadu, India in wet and dry seasons of 2015 and 2016 respectively in randomized block design with four replications. The treatments are pre- emergence application of Pendimethalin @ 1.0 kg ai ha-1 at 8 DAS followed by hand weeding at 25 DAS (T1 ), pre- emergence application of Pendimethalin @ 1.0 kg ai ha-1 at 8 DAS followed by post emergence application of Bispyribac sodium 25 g ha-1 at 25 DAS+ hand weeding at 45 DAS (T2 ) and Cono weeder weeding at 10 and 25 DAS (T3 ), Hand weeding on 15 and 30 DAS (T4 ) and Control - Weedy check (T5 ). The results revealed that, among the different weed control treatments, application of pre-emergence herbicide pendimethalin 1.0 kg ai ha-1 at 8 DAS with POE Bispyribac sodium 25g ha-1 at 25 DAS and HW on 45 DAS (T2 ) recorded higher grain yield of 6438 kg ha-1 with the B:C ratio of 2.77. With respect to weed control efficiency, application of pre-emergence herbicide pendimethalin 1.0 kg ai ha-1 at 8 DAS with POE Bispyribac sodium 25g ha-1 at 25 DAS and HW on 45 DAS (T2 ) recorded higher weed control efficiency of 81.0 % as compared with Cono weeder weeding at 10 and 25 DAS. Hence, it was concluded that considering the weed control efficiency, yield and economics, pre-emergence application of pendimethalin 1.0 kg ai ha-1 at 8 DAS with POE Bispyribac sodium 25g ha-1 at 25 DAS and HW on 45 DAS is recommended for weed management in direct seeded puddled rice to meet the challenges against labour scarcity and weed infestation in the field of small and marginal farmers.

Non-target effect of bispyribac sodium on soil microbial community in paddy soil.

Bispyribac sodium is frequently used herbicide in the rice field. Though, it has been targeted to kill rice weeds, but its non-target effect on soil microbes in paddy soil was largely unknown. Therefore, in the present study, an attempt was made to assess the non-target effect of bispyribac sodium on alteration of functional variation of soil microbial community and their correlation with microbial biomass carbon (MBC) and soil enzymes. A microcosm experiment set up was made comprising three treatments viz., control (CON) (without application of bispyribac sodium), recommended dose of bispyribac sodium (35gha-1) (BS), and double the dose of BS (70gha-1) (DBS). Results indicated that the MBC and soil enzyme activities (dehydrogenase, alkaline phosphatase and urease) in BS and DBS-treated soil were significantly (p<0.05) declined from 1st to 30th day after application as compared to CON. Counts of heterotrophic bacteria, actinomycetes and fungal population were also decreased in BS and DBS-treated soil. The average well color development (AWCD) values derived from Biolog®ecoplates followed the order of DBS ˂ BS ˂ CON. Shannon index value was high (p≤0.05) in CON compared to soil-treated with BS and DBS. Principal component analysis (PCA) showed a clear distinction of the cluster of treatments between CON, BS and DBS. Biplot analysis and heatmap suggested that carboxylic compounds and amino acids showed positive response towards BS-treated soil, whereas phenolic compounds had positive correlation with DBS-treated soil. PCA analysis indicated that oligotrophs was rich in BS-treated paddy soil, whereas copiotrophs and asymbiotic nitrogen fixers were richer in DBS treatment. Overall, the present study revealed that application of recommended dose of BS and its double dose alter the soil microbial population, enzyme activities and functional microbial diversity in paddy soil.

First Report of Herbicide-Resistant Echinochloa crus-galli in Uruguayan Rice Fields

Echinochloa crus-galli is the main weed in direct dry-seeded rice systems worldwide and is the target of most herbicide applications. Numerous cases of E. crus-galli biotypes with resistance to herbicides have been reported in different regions of the world; however, to date, no cases have been reported in Uruguay. The purpose of this research is to assess the presence of herbicide-resistant E. crus-galli in the rice fields of Uruguay. More than 40 E. crus-galli biotypes were sampled from eastern to northern regions in different years and assessed following the Herbicide Resistance Action Committee (HRAC) protocols of confirmation, using the herbicides propanil, quinclorac, clomazone, bispyribac–sodium, penoxsulam, imazapyr + imazapic, profoxidim and cyhalofop. Herbicides rates included 0, 0.125, 0.25, 0.50, 1, 2, 4 and 8 times the label rate. Most E. crus-galli biotypes (35) resulted as resistant to quinclorac. Furthermore, resistance was confirmed to propanil in at least seven biotypes, 12 to imazapyr + imazapic, and three to penoxsulam. Five biotypes showed multiple resistance to propanil and quinclorac, and one biotype was resistant to quinclorac, penoxsulam and imazapyr + imazapic. No biotype showed confirmed resistance to clomazone, bispyribac-sodium, cyhalofop or profoxidim—herbicides that ensure satisfactory control. The presence of E. crus-galli herbicide resistant-biotypes reduces herbicide options, threatening rice production in Uruguay. In this context, a redesign of the productive systems would represent an opportunity to complement the chemical control, integrating larger-scale cultural and management practices.

Lethal and parasitism effects of selected novel pesticides on adult Trichogramma chilonis (Hymenoptera: Trichogrammatidae)

Integration of chemical and biological controls is an important tactic of integrated pest management. Trichogramma chilonis (Ishii) is an important natural enemy of lepidopteran pests. However, the minute parasitoids are adversely affected by most pesticides. Effects of acute mortality and parasitism of selected novel pesticides on adults of T. chilonis exposed to the dried residues of field doses for 24 h on glass surface were evaluated. Acetamiprid, spinetoram and fipronil induced mortality of > 95%, followed by abamectin (ranged 71.3–83.5%) in four residual-age treatments. Spiromesifen, haloxyfop-p-methyl, mixture of pyraclostrobin + metiram and mixture of trifloxystrobin + tebuconazole revealed mortality of ≤ 36.4% in all treatments (when female parasitoids were exposed to 1 day, 5 days, 10 days and 15 days after treatments). Bispyribac sodium induced mortality of ranged 51.1–54.9% in 1- and 5-day treatments, and approximately ≤ 10% in others (10-day and 15-day treatment). Eggs of Sitotroga cerealella in acetamiprid, spinetoram, fipronil and abamectin treatments showed ≤ 36% parasitism relative to controls in all treatments. Spirotetramat, bispyribac sodium, nicosulfuron, trifloxystrobin + tebuconazole and pyraclostrobin + metiram resulted in parasitism rates of 49.2–71.2% and 81.5–93.8% in 1-day and 15-day treatment, respectively. Helicoverpa armigera nucleopolyhedrovirus, chlorantraniprole, spiromesifen haloxyfop-p-methyl, chlorothalonil + procymidone and myclobutanil showed ≥ 80.6% parasitism in all treatments. Thus, acetamiprid, spinetoram, fipronil and abamectin were the most harmful among the pesticides used for both emergence and parasitism, while remaining pesticides demonstrated relatively compatibility with the emergence as well as parasitism by the minute parasitoids, and can be integrated with the minute parasitoid in agroecosystem.

Behaviour of bispyribac-sodium in aerobic and anaerobic rice-growing conditions with and without olive-mill waste amendment

Water and tillage management practices alone or in combination with organic amendments can alter the behaviour of pesticides. This study evaluates the sorption, persistence, and leaching of bispyribac-sodium (BYS) under anaerobic and aerobic rice-growing conditions with and without soil amendment by composted olive mill waste (OW). For this purpose, field experiments were conducted over three years. They involved six treatments: no-tillage and sprinkler irrigation (aerobic) without (NTA) and with OW application (NTAOW), tillage and aerobic without (TA) and with OW application (TAOW), and tillage and flooding without (TF) and with OW application (TFOW). In all three OW treatments, the amendment was applied in the first year. The Kf values were significantly greater in TF than in [NTA and TA] for the first and third years of the experiment by factors of [1.5 and 2.3] and [1.6 and 1.2], respectively. While in the first year Kf was 1.5 times greater in TF than TFOW, at the end of the experiment it was 1.6 times lower. In the non-amended treatments, the persistence of BYS was up to 1.9 times greater under anaerobic than under aerobic incubation conditions. Except for the NTA treatment in the third year, the persistence of BYS under aerobic incubation conditions (t1/2 = 35.5–53.7 d) was enhanced when OW was applied to the soil (t1/2 = 44.5–80.1 d). Under anaerobic incubation conditions, in the first year the BYS persistence was significantly reduced in NTA and TA when OW was added to the soil, but in TF it was enhanced. Conversely, in the third year the persistence of BYS was significantly increased in NTA and TA by OW addition, but decreased under TF management. BYS leaching was similar under the aerobic (TA and NTA) and anaerobic (TF) treatments in the first year, but was less under the TF treatment at the end of the experiment. Independently of the water and tillage management, the addition of OW significantly influenced BYS sorption and persistence, reducing the amount of the herbicide leached, although the magnitude of the effect depended on the time elapsed after its application to the soil. The use of OW could be considered as a strategy with which to reduce water contamination by BYS under aerobic and anaerobic rice-growing conditions, especially in the short term after application of this organic amendment.

Integrated weed management in direct-seeded rice: dynamics and economics

Weeds are often the most severe problem in direct-seeded rice (Oryza sativa L.) (DSR), causes reductions in yield and profitability. The traditional method of controlling rice weeds or manual weeding has several demerits as the practice is uneconomical and difficult. The effects of 10 different weed management practices were evaluated to identify the most effective and economical methods of managing weeds in DSR during in Nepal during the rainy season of 2010. Pendimethalin was applied pre-emergence where 2,4-D, bispyribac sodium, and oxadiargyl were applied post-emergence alone or combined with hand weeding. Sesbania (Sesbania aculeata Wild. Pers.) was co-cultured with rice and killed by 2,4-D. Weed emergence, density, and biomass per unit area of 3 weed types: broadleaf, sedges, and grasses were assessed during 20, 40, 60 days after seeding (DAS), and at harvest. Treatments were compared either to weedy check or weed-free control to determine weed control indices. A total of 42 weed species belonging to 27 genera and 11 families emerged across the growing season of rice. Most of the weeds were annual where broadleaf and sedges were dominant during the first two months, and grasses were dominant under flooding. Weeds reduced the rice yield by more than 80% in weedy-check with respect to weed-free control. A sequential application of pendimethalin as pre-emergence and bispyribac-sodium postemergence herbicides followed by a hand weeding at 45 DAS provided up to 85% weed control over weedy check than other weed control measures. However, that method found uneconomical when compared to the same without hand weeding because of the high cost of manual labor. Pendimethalin was effective in controlling early flush of weeds and bispyribac efficiently controlled weeds even after flooding turned out to be a less expensive method controlling in DSR. An integrated approach of weed management including both pre-emergence and post-emergence herbicides can provide season-long weed control greater economic return.

Residual effect of nitrogen levels and weed control methods on growth, yield and economics of wheat grown after rice

A field experiment was laid out in split plot design on residual effect of treatments comprising three nitrogen levels viz. N75 (N1), N100 (N2) and N125 (N3) in main-plot treatments and seven weed control treatments viz. (W1-butachlor + 1 Hand Weeding, W2-butachlor + 2 Mechanical Weeding, W3-butachlor + 2,4-D, W4-bispyribac sodium, W5-butachlor + bispyribac sodium, W6-HW-2, W7- control) as sub-plot treatments conducted during 2015-16 and 2016-17 at the Rajaula Agriculture Farm, MGCGVV, Satna (M.P.) to study the residual effect of N-levels and weed control methods on growth, yield and economics of wheat grown after rice. In case of succeeding wheat, the residual 125 kg N/ha performed the best with respect to growth, yield-attributes with the result 31.11 q/ha grain yield and Rs.33509/ha income. While, under sub plot treatments, Hand weedings two times were recorded significant grain yield (28.66 q/ha) and straw yield (38.17 q/ha) at (P &lt;0.05) over control. However it was found non-significant different and also noticed higher over rest treatments. In this succession, Butachlor + 2, 4-D (0.80 kg/ha) was higher but in second position and similar trend was observed in successive way with rest of treatments.

Effect of Weed Management Practices on Crop Growth, Yield and Economics of Direct Seeded Rice Ecosystems

A field trial was carried out in Central Farm of Agricultural College and Research Institute, Madurai during rabi (late samba), 2018-19 to study the effect of weed management on crop growth, yield and economics of rice under various ecosystems. The experiment was laid out in strip plot design with twenty-eight treatment combinations and replicated thrice. The results revealed that among sowing methods, plant height, LAI, LAD, CGR, DMP and yield were observed higher under wet seeded condition whereas, in weed management practices weed free upto panicle initiation stage and the application of Bensulfuron methyl (0.6%) + Pretilachlor (6% GR) (10 kg ha-1) fb 2,4-D (1.25 kg a.i. ha-1) + one hand weeding at 45 DAS showed higher results. The economic analysis revealed that among the methods of sowing, net income and B:C ratio was found higher in puddled condition. Among various weed management practices, higher net return and B:C ratio was observed with the application of Bensulfuron methyl (0.6%) + Pretilachlor (6% GR) (10 kg ha-1) fb 2,4-D (1.25 kg a.i. ha-1) + one hand weeding at 45 DAS. It was followed by the application of Pendimethalin (2.5 kg a.i. ha-1) + Bispyribac sodium (50 g a.i. ha-1) fb one hand weeding at 45 DAS.

Enhanced remediation of bispyribac sodium by wheat (Triticum aestivum) and a bispyribac sodium degrading bacterial consortium (BDAM)

The use of plant-bacterial association is a promising approach for the enhanced remediation of pesticides. Generally, both rhizo- and endosphere bacteria assist their host plants to survive in the contaminated environment. In this work, we have studied the individual and combined effects of wheat (Triticum aestivum) and a previously optimized bispyribac sodium (BS) degrading bacterial consortium (BDAM) on the degradation of BS and plant biomass production. Results showed that the bacterial strains of the BDAM have successfully survived in the plant rhizo-as well as endosphere and enhanced degradation of BS and plant biomass. In soil spiked with 2 mg/kg and 5 mg/kg of BS and was planted and inoculated with BDAM (P_I) showed 100% degradation of BS both in rhizosphere soil and endosphere of the plant. However, during the same period (45 days) the degradation of BS was 96 and 90%, and 93 and 84% in inoculated but un-planted (I_UP) and planted but un-inoculated (P_UI) soils spiked with 2 and 5 mg/kg, respectively. Liquid chromatography-mass spectrometry (LC-MS) analysis of the treated samples showed novel degradation products of BS. Based on the results, we concluded that plant-bacterial association is an efficient tool for enhanced remediation of BS contaminated soil and herbicide free crop production.

Application of a novel bacterial consortium BDAM for bioremediation of bispyribac sodium in wheat vegetated soil.

Plant-bacterial mutualism has tremendous potential for remediation of herbicide contaminated soils. Generally, bacterial inoculation helps plants to grow well in the contaminated environment. Here, we investigated the impact of bispyribac sodium (BS) degrading bacterial consortium (BDAM) on BS remediation, plant growth promotion and BS accumulation in plant parts. Wheat (Triticum aestivum) was planted in BS spiked soil and inoculated with BDAM. Inoculation showed a beneficial effect on plant biomass production and degradation of BS in the rhizosphere and the rhizosheath. After 40 and 60 days of inoculation, the degradation of BS was more than 96% and approximately 100% respectively in the planted and inoculated soil spiked with 2 and 5 mg kg-1 BS. However, in planted and un-inoculated soil, the degradation of BS was 72% after 60 days of sowing. Furthermore, inoculated bacterial strains colonized both in rhizo- and endosphere of the inoculated plants. In comparison with the un-inoculated soil, significantly less accumulation of BS was found in the roots and shoots of the plants growing in inoculated soil. We report the efficiency of plant-bacterial partnership for enhanced biodegradation of BS and to eliminate the BS residual toxicity to non-target plants.

Weed growth, herbicide efficacy, and rice productivity in dry seeded paddy field under different wheat stubble management methods

To ascertain the influence of wheat stubble management options and chemical weed control methods on weed growth and productivity of dry direct-seeded fine rice, a two years' field study was undertaken at the Agronomic Research Farm, University of Agriculture, Faisalabad, Pakistan in 2013 and 2014. Different wheat stubble management methods, viz., incorporation, burning and retention were executed during seed-bed preparation. While, herbicide treatments comprised of a weed check, weed free, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl, and bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl. Results revealed that weed control efficacy of both herbicide treatments ranged from 84 to 94%. Herbicide treatments significantly reduced weed density (88–90%) and dry weight (86–88%), while improved the rice growth attributes compared with weed check. Application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention recorded 226 and 273% increase in kernel yield over weedy check in 2013 and 2014, respectively. In stubble incorporation, pendimethalin followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl was more effective in increasing (256–293%) rice yields over weedy check. Among different treatment combinations, the maximum net benefits (1397.49–1472.22 USD ha−1), net returns (636–700 USD ha−1), benefit cost ratio (1.77–1.83) and marginal rate of return (2187–2330%) were recorded with the application of bispyribac sodium followed by fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention. In crux, application of bispyribac sodium followed by tank mixture of fenoxaprop p-ethyl+ethoxysulfuron ethyl in stubble retention is efficient approach to control weeds, and get maximum rice productivity and net economic returns under dry seeded system.